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Biomedical subjects

D J Kim

Publications and source records attributed to D J Kim.

At least 181 records · Page 10Linked to original sources
PubMed1994

Intracellular expression of Vitreoscilla hemoglobin alters Escherichia coli energy metabolism under oxygen-limited conditions.

An earlier stoichiometric analysis of oxygen-limited metabolism of Escherichia coli expressing cloned Vitreoscilla hemoglobin (VHb) suggested improved efficiency of ATP production relative to wild-type controls [Khosla, C., Curtis, J. E., DeModena, J., Rinas, J. & Bailey, J. E. (1990) BioTechnol. 8, 849-853]. This hypothesis has been further examined by determining several energetic parameters of different VHb-expressing E. coli (VHb+) strains relative to controls not expressing VHb (VHb-). The H+/O ratio, the transmembrane delta pH, and the ATP content of VHb+ constructs are 1.5, 1.6 and 2 times, respectively, corresponding values in VHb- controls. VHb was expressed using a low-copy-number vector in E. coli mutant strains lacking cytochrome o, cytochrome d, or both terminal oxidases; significant growth enhancement due to VHb expression was observed only in the strain having functional cytochrome o and lacking cytochrome d. All of these data obtained using different E. coli strains are consistent with a model of VHb action that hypothesizes enhancement by VHb of activity of the lower oxygen-affinity, higher proton-pumping-efficiency cytochrome o terminal oxidase under oxygen-limited growth conditions.

Aerobiosis↗
PubMed1994

Expression of a single gene encoding microbody NAD-malate dehydrogenase during glyoxysome and peroxisome development in cucumber.

A full-length cDNA clone encoding microbody NAD(+)-dependent malate dehydrogenase (MDH) of cucumber has been isolated. The deduced amino acid sequence is 97% identical to glyoxysomal MDH (gMDH) of watermelon, including the amino terminal putative transit peptide. The cucumber genome contains only a single copy of this gene. Expression of this mdh gene increases dramatically in cotyledons during the few days immediately following seed imbibition, in parallel with genes encoding isocitrate lyase (ICL) and malate synthase (MS), two glyoxylate cycle enzymes. The level of MDH, ICL and MS mRNAs then declines, but then MDH mRNA increases again together with that of peroxisomal NAD(+)-dependent hydroxypyruvate reductase (HPR). The mdh gene is also expressed during cotyledon senescence, together with hpr, icl and ms genes. These results indicate that a single gene encodes MDH which functions in both glyoxysomes and peroxisomes. In contrast to icl and ms genes, expression of the mdh gene is not activated by incubating detached green cotyledons in the dark, nor is it affected by exogenous sucrose in the incubation medium. The function of this microbody MDH and the regulation of its synthesis are discussed.

Amino Acid Sequence↗
PubMed1994

Molecular cloning of cucumber phosphoenolpyruvate carboxykinase and developmental regulation of gene expression.

A cDNA library from RNA of senescing cucumber cotyledons was screened for sequences also expressed in cotyledons during post-germinative growth. One clone encodes ATP-dependent phosphoenolpyruvate carboxykinase (PCK; EC 4.1.1.49), an enzyme of the gluconeogenic pathway. The sequence of a full-length cDNA predicts a polypeptide of 74,397 Da which is 43%, 49% and 57% identical to bacterial, trypanosome and yeast enzymes, respectively. The cDNA was expressed in Escherichia coli and antibodies raised against the resultant protein. The antibody recognises a single polypeptide of ca. 74 kDa, in extracts of cotyledons, leaves and roots. The cucumber genome contains a single pck gene. In the seven-day period after seed imbibition, PCK mRNA and protein steady-state levels increase in amount in cotyledons, peaking at days 2 and 3 respectively, and then decrease. Both accumulate again to a low level in senescing cotyledons. This pattern of gene expression is similar to that of isocitrate lyase (ICL) and malate synthase (MS). When green cotyledons are detached from seedlings and incubated in the dark, ICL and MS mRNAs increase rapidly in amount but PCK mRNA does not. Therefore it seems unlikely that the glyoxylate cycle serves primarily a gluconeogenic role in starved (detached) cotyledons, in contrast to post-germinative and senescing cotyledons where PCK, ICL and MS are coordinately synthesised. While exogenous sucrose greatly represses expression of icl and ms genes in dark-incubated cotyledons, it has a smaller effect on the level of PCK mRNA.

Amino Acid Sequence↗
PubMed1994

Effect of nicotine, lobeline, and mecamylamine on sensory gating in the rat.

In normal subjects, if an acoustic startle stimulus is immediately preceded by a small brief change in background noise intensity, the magnitude of the subsequent startle response is decreased. This prepulse inhibition (PPI) of an acoustic startle response has been shown to be associated with sensorimotor gating. PPI is disrupted in schizophrenic patients and has been linked to attentional disorders characteristic of this disease. We tested the effects of (-)-nicotine, (0.19, 0.62, and 1.9 mumol/kg IP) (equivalent to 0.03, 0.1, and 0.3 mg/kg base) and the nicotinic cholinergic receptor (nAChR) channel blocker, mecamylamine (5.0 and 50 mumol/kg IP) (equivalent to 1.0 and 10.0 mg/kg) on PPI of the acoustic startle response in the rat. Nicotine increased the PPI at the lowest prepulse signal levels but not at the stronger levels. Mecamylamine was without effect at 5.0 mumol/kg, but the 50 mumol/kg dose decreased the inhibition at both weak and strong prepulse (PP) levels. Mecamylamine (5.0 mumol/kg) pretreatment did not block the (-)-nicotine-induced increase in PPI. Lobeline (0.19, 0.62, 1.9, and 6.2 mumol/kg IP) (equivalent to 0.071, 0.23, 0.71, and 2.3 mg/kg) was without effect. These results are consistent with a mecamylamine-insensitive effect of nicotine to improve gating in normal rats. The nAChR subtype involved in producing nicotine's increase of PPI needs further investigation.

Acoustic Stimulation↗
PubMed1994

Prothrombin Padua I: incomplete activation due to an amino acid substitution at a factor Xa cleavage site.

An individual and an affected brother previously identified as having the variant prothrombin Padua I were studied in order to identify underlying genetic defects. A heterozygous mutation in the prothrombin gene exon 8 was identified as substitution of A for G at nucleotide position 7,312 (Arg271 (CGT) to His (CAT)). An abolished RsaI restriction site was used to confirm heterozygosity for the defect. Lack of the requisite cleavage of the His271-Thr272 bond in prothrombin Padua I could prevent release of fragment 2 and block the conversion of the intermediate meizothrombin des fragment 1 to alpha-thrombin, providing an explanation of reduced potential for clotting activity and for the observed mild bleeding tendency.

Amino Acid Sequence↗
PubMed1994

Biphasic modifying effect of indole-3-carbinol on diethylnitrosamine-induced preneoplastic glutathione S-transferase placental form-positive liver cell foci in Sprague-Dawley rats.

The biphasic modifying effects of indole-3-carbinol (I3C), a naturally occurring constituent of edible cruciferous vegetables, on the development of glutathione S-transferase placental form (GST-P)-positive liver cell foci were investigated by using a medium-term liver bioassay system and a newborn rat hepatocarcinogenesis system. In Experiment 1, a total of 65 male Sprague-Dawley (SD) rats were divided into 5 groups. Animals were given a single intraperitoneal (i.p.) injection of 200 mg/kg diethylnitrosamine (DEN) dissolved in saline for groups 1, 2, and 3 or a single i.p. injection of saline for groups 4 and 5. Group 1 was given the diet containing 0.25% I3C for 2 weeks prior to DEN initiation and then basal diet for 8 weeks. Group 2 was given basal diet for 4 weeks prior to and after DEN initiation and then the diet containing 0.25% I3C for 6 weeks. The rats of group 3 were placed on basal diet during the experiment. Animals of groups 4 and 5 were treated in the same manner as those of groups 1 and 2 except for injection with saline instead of DEN solution. All rats were subjected to two-thirds partial hepatectomy at week 3 and were killed at week 8 after DEN or saline injection. In Experiment 2, a total of 45 female SD rats were dosed with DEN (100 mg/kg, i.p.) or saline at 24 h after birth. After weaning at week 3, the rats were fed diet containing 0.25% I3C for 9 weeks and then were killed at week 12. In Experiment 1, preinitiation exposure to 0.25% I3C caused a significant decrease in numbers of GST-P-positive liver cell foci (P < 0.05), while postinitiation exposure to 0.25% I3C caused significant increases in both number (No./cm2) and area (mm2/cm2) of GST-P-positive liver cell foci (P < 0.05 or 0.01). In Experiment 2, the relative liver weight in the DEN + I3C group was significantly increased (P < 0.001). The numbers and areas of GST-P-positive liver cell foci in the DEN + I3C group were significantly increased as compared to the values of the DEN-alone group (P < 0.001). These results clearly demonstrated that I3C exerts a promoting effect on the postinitiation stage as well as an inhibitory effect on the preinitiation stage in the medium-term liver bioassay.

Animals↗
PubMed1994

Culture of tissue-cyst forming strain of Toxoplasma gondii and the effect of cyclic AMP and pyrimidine salvage inhibitors.

An in vitro culturing to examine the cyst stage of Toxoplasma gondii (ME49 strain) was investigated using murine peritoneal macrophages, and we also examined the effect of cAMP or DHFR inhibitors on the growth of bradyzoites. For experiments ICR mice were injected i.p. with 1,500 brain cysts. At 1, 3, 5 and 7 days, peritoneal exudates were isolated and then adherent peritoneal macrophages were cultured for 1, 3, 5 and 10 days. Growth pattern of bradyzoites was measured by [3H]-uracil uptake assay and morphological pattern of pseudocysts formed in macrophages was observed with Giemsa stain. Mostly bradyzoites were observed in the macrophages extracted at 3 and 5 days post infection. After 3 days in vitro, a number of pseudocysts were formed in the macrophages and the size of pseudocysts was increased during further 5 and 10 days in vitro culture. cAMP stimulated the growth of bradyzoites when in vivo 3 and 5 days and then in vitro 5 and 10 days conditions were applied. In case of DHFR inhibitors, pyrimethamine produced a linearly decremental effect with a conc.-dependent mode but methotrexate was not effective against intracellular bradyzoites or pseudocysts in this system. It was suggested that cyst-forming strain of T. gondii (ME49 strain) could be maintained and cultivated in vitro by use of murine peritoneal macrophages. In vivo 3 and 5 days and then in vitro 5 and 10 days conditions appeared to be suitable for culturing of bradyzoites. cAMP and pyrimethamine had an effect of stimulation and inhibition on the growth of bradyzoite, respectively.

Animals↗
PubMed1994

(S)-3-methyl-5-(1-methyl-2-pyrrolidinyl)isoxazole (ABT 418): a novel cholinergic ligand with cognition-enhancing and anxiolytic activities: II. In vivo characterization.

(S)-3-methyl-5-(1-methyl-2-pyrrolidinyl)isoxazole (ABT 418), an isoxazole analog of (-)-nicotine, is a potent agonist at the alpha-4/beta-2 subtype of neuronal nicotinic acetylcholine receptor (nAChR) that exists in mammalian brain (Arneric et al., 1994). Compared to (-)-nicotine, ABT 418 has reduced potency to interact with the subunit isoforms of nAChR found in sympathetic ganglia, and it does not compete for alpha-bungarotoxin binding sites in brain or at the neuromuscular junction. ABT 418 [minimum effective dose (MED), 0.062 mumol/kg i.p.) was 10-fold more potent in improving retention of avoidance learning in normal mice than (-)-nicotine, whereas the (R)-enantiomer of ABT 418, A-81754, was inactive. The memory-enhancing effect of ABT 418 was prevented by the nAChR channel blocker, mecamylamine. In the elevated plus-maze model of anxiety, ABT 418 (MED, 0.19 mumol/kg i.p.) increased open-arm exploration in mice, as previously shown for (-)-nicotine (MED, 0.62 mumol/kg i.p.). A-81754, did not have anxiolytic-like effects in this test. Unlike the classical anxiolytic, diazepam, ABT 418 did not impair rotorod performance in the dose range where beneficial effects occurred. In rats, ABT 418 (MED, 0.002 mumol/kg i.v.) was remarkably potent in enhancing basal forebrain-elicited increases in cortical cerebral blood flow, whereas resting cerebral blood flow was unaffected. Free running cortical electroencephalography in rats was unaffected by ABT 418 at a dose of 1.9 mumol/kg i.p., whereas the same dose of (-)-nicotine caused cortical activation (decreased power in the 1-13 Hz range and increased power in the 25-50 Hz range). Whereas ABT 418 was approximately 3- to 10-fold more potent than (-)-nicotine in memory enhancement and anxiolytic test paradigms, the compound had less emetic liability in dogs as compared to (-)-nicotine, and was less potent than (-)-nicotine in eliciting hypothermia, seizures, death and reduction of locomotor activity in mice. The measured pharmacokinetic or brain disposition properties of ABT 418 in rats did not account for the observed enhancement in efficacy with reduced toxicity as compared to (-)-nicotine. The potent cognitive-enhancing and anxiolytic properties obtained for ABT 418 in animal models without eliciting significant side effects suggest that this ligand is a selective activator of cholinergic channel-mediated behaviors. Thus, ABT 418 may represent a novel, safe and effective treatment of the cognitive and emotional dysfunctions associated with Alzheimer's disease.

Alzheimer Disease↗
PubMed1994

Allogeneic bone marrow transplantation in Korea: 1983-92.

Between March 1983 and December 1992, we performed 178 allogeneic BMTs for patients with hematopoietic stem cell disorders: 48 acute myelogenous leukemia (AML), 27 acute lymphoblastic leukemia (ALL), 40 chronic myelogenous leukemia (CML), 55 severe aplastic anemia (SAA), 6 myelodysplastic syndrome (MDS), 1 non-Hodgkin's lymphoma and 1 hybrid leukemia. Twenty-five of 48 AML are in disease-free survival (DFS). Fifteen of 27 ALL are in unmaintained remission. Twenty-four of 40 CML are in DFS. Forty-four out of 55 SAA patients are alive and well. Comparing the survival between standard (< or = CR1: 21 of 31 (68%)) and high risk (> or = CR2: 4 of 17 (24%)) AML, our data suggest that the preparative regimen for high risk AML was not potent enough to eradicate the residual disease in advanced AML. Although our cases are limited and the follow-up period is short, the result of ALL (overall: 56%, standard risk (adult < or = CR1, children < or = CR2: 10 of 14 (71%) and high risk (adult > or = CR2, children > CR2): 5 of 13 (38%)) and CML (overall: 60%; CP: 19 of 27 (70%), AP or BC: 5 of 13 (38%)) are promising. The probability of 5 year survival of SAA was 80 +/- 4 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Anxiolytic-like effects of the novel cholinergic channel activator ABT-418.

The hydrochloride salt of (S)-3-methyl-5-(1-methyl-2-pyrrolidinyl) isoxazole (ABT-418), a potent activator of select subtypes of neuronal nicotinic acetylcholine receptors enhanced retention in memory tests and induced anxiolytic-like effects in mice in the elevated plus maze. In the present studies in rats, ABT-418 induced a significant increase in the time spent by the rats in the open arms of the elevated plus maze (0.62 mumol/kg i.p.); the effect persisted up to 60 min after the injection and was blocked by mecamylamine (15 mumol/kg), a centrally acting nicotinic acetylcholine receptor channel blocker. ABT-418 was 6-fold and 1.6-fold more potent than diazepam and ondansetron, respectively. The anxiolytic-like effect of ABT-418 was observed after oral administration in rats (10-30 mumol/kg) and at slightly higher doses in 20-month-old rats (1.9 mumol/kg i.p.). Major metabolites of ABT-418 [(S)-1-methyl-5-(3-methyl-5-isoxazolyl)-2-pyrrolidinone, cis-ABT-418 N-oxide and trans-ABT-418 N-oxide] were inactive in the plus maze in mice up to 6.2 mumol/kg, did not affect body temperature and had minimal effects on locomotion. Like (-)-nicotine, ABT-418 was effective (4 and 13 mumol kg-1 day-1) to induce anxiolytic-like effects after a 14-day treatment through minipumps implanted subcutaneously. Acute administration of ABT-418 (0.62 mumol/kg i.p.) also attenuated the anxiogenic-like effect elicited by withdrawal from chronic (-)-nicotine treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Nicotinic receptor agonists exhibit anxiolytic-like effects on the elevated plus-maze test.

The effects of nicotinic receptor agonists on the elevated plus-maze test of anxiety were investigated in CD1 mice after intraperitoneal injections. Nicotine and lobeline, but not cytisine, exhibited a significant increase in the time spent by the mice in the open arms, a measure of anxiolytic activity. Nicotine also increased the total number of arm entries, a measure of general activity, but this effect was secondary to its anxiolytic-like properties. Nicotinic receptor antagonists on their own did not modify the behavior of mice in the maze. The effect of nicotine was mediated by central nicotinic receptors as it was blocked by the centrally-acting nicotinic antagonists mecamylamine and chlorisondamine, but not by hexamethonium (a peripherally acting blocker). Cotinine, the major metabolite of nicotine, was evaluated at different times after systemic injections and had no effect in the plus-maze. The anxiolytic-like profile induced by nicotinic receptor stimulation was not associated with potentiation of alcohol effects, a liability associated with the benzodiazepine therapy. This study demonstrates the anxiolytic-like properties of nicotine and lobeline in mice, and suggests that central nicotinic receptors are involved in the expression of emotional behavior.

Alkaloids↗
PubMed1993

Inhibition of entry of Toxoplasma gondii into MDCK cells by fetal bovine serum.

We experienced the partial inhibition of entry of Toxoplasma gondii into MDCK cells when the FBS was depleted from media. MDCK cells and Toxoplasma (RH strain) were co-cultured, the penetration was inhibited up to 60-80% with concentration-dependence of FBS. Inhibitory effect was clear when the conc. of FBS was over 1% (v/v) with 50% inhibition conc. of 5%. When Toxoplasma was pre-incubated with FBS and then applied to MDCK cells, there were no inhibitory effect, but when FBS was added to Toxoplasma-MDCK co-culture, the time of adding was critical with rapid inhibition. And when FBS was further treated with heat (95 degrees C, 10 min), the inhibitory effect was decreased slightly in both raw and inactivated FBS. The FBS factor(s) might participate to neutralize secreted materials which enhancing penetration or intervene between receptor-ligand binding at the moment of entry through sterically rather than functionally.

Animals↗
PubMed1992

Effect of acyl derivatives of 4,4,4-trifluoro-1-phenyl-1,3-butanedione on 2-acetylaminofluorene-induced glutathione S-transferase positive foci in the rat liver.

Acyl derivatives of 4,4,4-trifluoro-1-phenyl-1,3-butanedione (TFPB), 1-benzoyl-2-trifluoromethyl-2-acetoxyethene (BTAE), and 1-benzoyl-2-trifluoromethyl-2-(4-methylthio)benzoyloxyethene (BTME), were synthesized and investigated for inhibition of tRNA binding by N-acetoxy-2-acetylaminofluorene (N-AcO-AAF), and induction of glutathione S-transferase placental form (GST-P) positive foci in the rat liver by 2-acetylaminofluorene (2-AAF). Male F344 rats were given BTAE or BTME intraperitoneally and 2-AAF by intragastric intubation. Two weeks following the treatment, the rats were maintained on the diet containing 0.05% phenobarbital for an additional 6 weeks and then killed. Development of GST-P positive foci was not affected by concomitant treatment with BTAE or BTME. These two compounds inhibited the in vitro binding of N-AcO-AAF to tRNA. Thus, although these diacylmethane derivatives had the in vitro inhibitory activity, they did not inhibit tumor-initiating activity of 2-AAF in the rat liver.

2-Acetylaminofluorene↗
PubMed1992

Human fetal heart development after mid-term: morphometry and ultrastructural study.

A total of 44 normally developed human fetal hearts aged from 17 to 40 weeks gestation were provided for routine ultrastructural and morphometric studies. For morphometric analysis, the maximal thicknesses of the anterior, lateral and posterior wall of both ventricles and that of interventricular septum were measured and the left-to-right thickness ratios calculated. The cross-sectional areas of both ventricles in the plane of the greatest heart diameter were measured with computerized image analysis system. Data were analyzed using linear regression and one-way analysis of variance. Myofibril formation occurred by attachment of thin filaments into amorphous Z materials which were presented in sarcolemmal plaques, sarcoplasmic condensations, desmosomes and in Z lines. From these Z centers, myofibrils radiated many directions and branched and anastomosed with further development. This pattern of myofibrillar development continued throughout the whole fetal period. A transverse tubule system was clearly evident in later fetal development. It occurred by invagination of sarcolemma into myocardial cells and formation of subsarcolemmal caveolae. Mitochondria, well-developed Golgi complexes, glycogen granules and well-developed microvessels were found throughout the whole fetal period. Binucleated myocytes appeared by 32 weeks gestation and this suggests that myocyte hyperplasia may cease before birth in humans. The growth of both ventricular walls, the interventricular septum and that of both ventricular cross-sectional areas showed linear regression, and the left-to-right wall thickness ratios were nearly constant. Also, there were no differences in morphometric data between the left and right ventricles. In conclusion, development of the myocyte is an ongoing process which may be continued in the post-natal period in humans, and our statistical results do not support the theory of the right ventricular dominance during the fetal period.

Cell Differentiation↗
PubMed1992

Enhancement of GST-P-positive liver cell foci development by nivalenol, a trichothecene mycotoxin.

In order to elucidate whether T-2 toxin (T-2) and nivalenol (NIV), the naturally occurring trichothecene mycotoxins in food and feed, are carcinogenic or possess an ability to modulate aflatoxin B1 (AFB1)-induced hepatocarcinogenicity, a medium-term liver bioassay was carried out. F344 male rats were given a single i.p. injection of diethylnitrosamine (DEN, 200 mg/kg), and then fed the test trichothecenes in diet (2 and 5 p.p.m. T-2 or 6 p.p.m. NIV) for 6 weeks beginning 2 weeks after the injection. Some control groups received DEN alone. For synergism between AFB1 and the trichothecenes, DEN-initiated rats as above were given a single i.p. injection of AFB1 (0.5 mg/kg) 2 weeks later and were fed a NIV-containing diet (6 p.p.m.) for 6 weeks. The other control group received the vehicle alone. Control rats not initiated with DEN were also treated with AFB1, NIV or T-2 alone as above. All rats were subjected to a two-thirds partial hepatectomy (PH) at week 3 and killed at week 8, and liver sections were analyzed by glutathione S-transferase placental form (GST-P) expression. In rats that did not receive DEN, AFB1 alone enhanced both the numbers and areas of GST-P-positive foci as reported earlier, while NIV or T-2 alone induced no marked changes. In rats initiated with DEN, AFB1 caused a marked expression of GST-P, and thus the hepatocarcinogenicity of AFB1 was reconfirmed. The expression of GST-P foci in rats fed T-2 or NIV was found to be at background level, indicating that the hepatocarcinogenicity was not predicted for the trichothecene mycotoxins such as T-2 and NIV by this medium-term bioassay system. In the group initiated by DEN followed by AFB1, on the other hand, an elevation of both the numbers and areas of GST-P-positive foci was observed by the subsequent feeding of rats with NIV, and this elevation was statistically significant from the sum totals of individual data of AFB1 or NIV alone. From this evidence, it is predicted that NIV causes an enhancing effect on AFB1-induced hepatocarcinogenesis.

Animals↗
PubMed1992

Dose-dependent formation of preneoplastic foci and DNA adducts in rat liver with 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP).

Dose responses to two heterocyclic amines, 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeA alpha C) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), in induction of glutathione S-transferase placental form positive liver cell foci (GST-P+ foci) and DNA adduct formation in the liver were examined in male F344 rats. Beginning 2 weeks after a single diethylnitrosamine (DEN) injection (200 mg/kg, i.p.), rats received MeA alpha C or PhIP in the diet at various doses for 6 weeks. All rats were subjected to two-thirds partial hepatectomy (PH) 1 weeks after the test agents were added to the diet and were killed 8 weeks after DEN initiation. MeA alpha C (100, 200, 400 and 800 p.p.m.) significantly increased numbers and areas of GST-P+ foci over control levels in all dose groups with a clear dose-response. In contrast, PhIP (50, 100, 200 and 400 p.p.m.) only equivocally increased foci development in the highest dose group and rather was associated with decrease in the lower dose groups. DNA adduct formation assessed by 32P-postlabeling demonstrated a dose-dependent increase with both chemicals, the levels being much higher with MeA alpha C. Thus, two highly mutagenic heterocyclic amines that are produced in broiled foodstuffs exerted different influence on GST-P+ foci development and DNA adduct formation; these findings are consistent with liver carcinogenicity in rats and/or mice.

Animals↗
PubMed1992

Detection of antibodies in serum and cerebrospinal fluid to Toxoplasma gondii by indirect latex agglutination test and enzyme-linked immunosorbent assay.

Sensitivity of anti-Toxoplasma antibody (IgG) test by enzyme-linked immunosorbent assay (ELISA) was evaluated in comparison with indirect latex agglutination (ILA) using 2,016 paired human samples of serum and cerebrospinal fluid (CSF). The samples were collected from neurologic patients in Korea with mass lesions in central nervous system (CNS) as revealed by imaging diagnosis (CT/MRI). When the sera were screened for anti-Toxoplasma antibody by ILA, 76 cases(3.8%) were positive (1:32 or higher titers). In the paired samples of CSF, no positive reactions were observed. When ELISA was performed using PBS extract of Percoll purified tachyzoites as antigen, cut-off absorbance was determined as 0.40 for serum and 0.27 for CSF tests. The antibody positive rates by ELISA were 7.0% in serum and 5.6% in CSF. Of them, 40 cases (2.0%) showed positive reactions in both serum and CSF. The antibody positive rates were higher in groups older than 40 years. The rates were higher in male (4.7% by ILA, 8.3% by ELISA) than in female (2.2% by ILA, 5.0% by ELISA). The rates in CSF showed no such sex difference. ELISA showed twice higher positive rates when serum was tested, and was sensitive enough to detect specific antibodies in CSF. Etiologic relations between positive antibody tests and CNS lesions remained unknown.

Age Factors↗